The present invention relates to an electronic still single-lens reflex camera having an image sensor which subjects the image of an object to photoelectric conversion to obtain an electrical signal and the electrical signal thus obtained is recorded on a magnetic recording medium by a magnetic recording head. More particularly, the invention relates to a head loading device which pushes the recording medium against the recording head in an image signal recording operation.
In an electronic camera, an image sensor such as a solid-state image pickup element is used to obtain an electrical signal indicative of the brightness of the image of an object, and the electrical signal thus obtained is stored on a magnetic disc. Because the electronic camera employs an image sensor instead of film, the essential components of the camera other than the image sensor may be the same as those of a conventional film camera such as a still single-lens reflex camera. That is, the photometric device, the viewfinder optical system, the quick return mirror, the shutter and the lens stop of the still single-reflex camera can be used without modification to control exposure.
On the other hand, in the electronic still single-lens reflex camera, electrical signals provided by the image sensor are processed to be recorded on a recording medium, namely, a magnetic disk. In order to record the signals on the recording medium, a magnetic recording head is used. In the recording operation, the magnetic recording head should be in a loading state where it is in contact with the magnetic disk under a suitable contact pressure. However, when no recording operation is being carried out, such as when the recording head is moving radially of the magnetic disk, the recording head performs tracking, or when the magnetic disk is turned after the tracking operation, the recording head should be in an unloading state where it is held slightly away from the magnetic disk. In order to place the head in the loading state in the recording operation, the conventional electronic still single-lens camera uses a depressing pad or the like coupled to an electromagnetic device such as a direct advance solenoid to urge the magnetic disk against the magnetic recording head. However, the conventional head loading device, requiring an electromagnetic component such as the direct advance solenoid as its drive source, suffers from difficulties that it is intricate in construction and large in power consumption.